Spark plug



W. A. HEIDE April 1, 1924;

S PARK PLUG Filed une` l0 @uvam/to@ A @im Patented Apr. 1, 1924.

` 1,488,543 PATENT oFFlcE.

UNITED STATES WILLIAM A. HEIDI?.l OF DETROIT, MICHIGAN.

snm: PLUG.

Application led .Tune 10, 1920. Serial No. 387,972.

To all whom t may concern. i

Be it known that I, WILLIAM A. HEIDE, a citizen of the United States, residing at Detroit, in the county of Wayne and State of Michigan, have invented a new and useful Spark Plug, of which the following is a specification.

This invention relates to spark plugs, one of its objects being to provide means wherebly the accumulation of carbon between the e ectrodes can be prevented by setting up an intermittent circulation of airv or gas between the electrodes, such circulation being effected by the movement of the piston within the cylinder of the engine.

A further object is to provide simple and elicient means for holding the parts of the plug assembled, one of the electrodes being shiftable -relative to the other and having improved means for electrically connecting one of the terminals thereto..

With the foregoing and other objects in view, which will appear as` the description `proceeds, the invention resides in the commation and arrangement of parts and 1n' the details of construction hereinafter described and claimed, it being understood that, within the scope of what is claimed, changes in the precise embodiment of the invention shown can be made without departing from the spiritl of the invention.

In the accompanying drawings the preferred form of the invention has been shown.

In said drawings- Figure 1 is a section through a spark plug constructed in accordance with the present invention.

Fi re 2 is a plan view of one of the ter- Y mina s.

from the inner end of the porcelain core to Referring to the figures by characters of reference 1 designates the metal shell of the spark plug provided with an interior annular shoulder 2 and with an interiorly threaded end portion 3 adapted to be engaged by the usual type of pac ing nut 4. A orcelain core 5 `1s seated in the shell an held therein by the nut 4, this core bein provided, at its upper end, with an an ar extension 6 while projecting radially ilom the core between this extension and the nut 4 is a nose 7. A passage 8 is extended longitudinally from the inner end of the core 5 and terminates, opposite the nose 7, in a lateral extension 9 which is formed in the nose. 'Thus there is provided a continuous passage the external atmosphere. A bore or reduced assage 10 is formed in the extension 6 and tended longitudinally within the passage 8 and through the bore 10, this rod being rovided at its inner end with a conical hea 12 constituting the other electrode and which head is normally seated upon the flared lower or inner end 13 of the passage 8 so as to close said passage. A centering spider 14 or the like may be attached to the rod 11 so as to keep said rod properly positioned within the passage.

One end of the rod 11 projects through and beyond the extension 6 and is screw threaded, as shown at 15. Mounted on the extension 6 is a terminal plate 16 the corners of which are oifset, as at 17 so as to straddle the extension 6 and revent the plate from sliding out of position. This terminal plate has a central opening 18 from the wall of which are struck lingers 19. A coiled sprin 20 bears on the plate 16 and is held proper y centered by the fingers 1.9. This spring is housed within a cap 21 and a nut 22 which engages the threaded end 15 of the rod bearsron the cap. By means thereof the tension of the spring can be controlled and the electrode 12 can be caused to bear upon its seat 13 with any desired degree of pressure. One of the conducting wires has been indicated at 23 and is suitably connected to the terminal plate 16.

It will be understoodthat when the spark plug is in place the suction created by the piston will intermittently unseat the electrode 12 and at the same time will set up a current of air through the passage 8 and its extension 9, this current as well as the movement of the electrode 12 relative to the seat 13, serving to loosen and remove any carbon that might otherwise accumulate between the electrodes. The spring 20 and the parts engaged thereby insure a constant connection between this movable electrode and the terminal plate 16. This spring also constitutes means whereby the pressure -of the electrode upon its seat can be governed.

Obviously instead of opening the passage extension 9 directly to the external atmosphere, it can be connected to the intake manifold l,of the engine so that each time the elec trode 12 is unseatedI and a suction is set up,

a small amount of fuel will be drawn into the engine. t

If preferred the passage extension 9 can be connected with a suitable source of hot air such as a jacket housing the exhaust pipe of the engine. In this manner heated air can be supplied to the engine through the spark plug.

For the purpose of limiting the movement of the electrode l1 so that the valvel 12 will not open too far, an adjusting nut 24 can be mounted on the rod 11 and be secured by means of a lock nut 25.

What is claimed is;

The combination with a spark plug having an air supply passage opening therethrough and an electrode slidably mounted in the passa e and normally closin it, of a terminal pte mounted on one en of the spark plug and having offset portions straddling said end to hold the plate against rotation relative to the plug, a cap adjustably mounted upon the projecting end portion of the electrode, and a coiled spring housed Within the cap and bearing on the terminal plate for holding the electrode in normal or closed position and for making an eleotrical connection between the terminal plate and the cap and electrode, and upstruck portions on the plate projecting into one end of the spring.

In testimony that I claim the foregoing as my own, I have hereto afixed my signature in the presence of two Witnesses.

WILLIAM A. HEIDE.

Witnesses:

PHILIP A. LoERscH. EMMA LoERsoH. 

